Cellulose-nitrate composition and sheet



UNITED STATES PATENT OFFICE.

PAUL C. SEEL, HENRY COMIBS, AND RICHARD KEMP, OF ROCHESTER, NEW YORK,

ASSIGNORS T0 EASTMAN KODAK COMPANY, OF ROCHESTER, NEW YORK, A. GOR- PORATION OF NEW YORK.

CELLULOSE-NITRATE COMPOSITION AND SHEET.

No Drawing.

To all whom it may concern.

Be it known that we, PAUL C. SEEL, HENRY Comes, and RICHARD KEMP, citizens of the United States of America, residing at Rochester, in the county of Monroe and State of New York, have invented certain new and useful Improvements in Cellulose- Nitrate Compositions and Sheets, of which the following is a full, clear, and exact specification.

This invention relates to a new simplified nitrocellulose com osition and to films or sheets made there rom. K

In the manufacture of flowed sheets, such, for example, as those used as supports for sensitive photographic coatings, the composition employed should yield films having enduring strength, transparency, flexibility, desired thinness, water-proof quality, resistance to photographic baths, resistance to scratching and heat, no. harmful efi'ect on the sensitive coating, and the quality of being unitable to such coating by the usual substratums. During manufacture the composition should be sufiiciently thick and viscous to flow to the right thickness, yet be capable of filtration. The volatile and non-volatile or high-boiling in redients should be of such nature that the rylng of the sheet will not cockle, pit, or cloud it. Of course, the composition should not injure or be injured by the substances and machines with which it contacts during compounding and manufacture. It is the principal object of our invention to produce by simplification a composition and film having the above qualifications without employing expensive or troublesome ingredients which have heretofore been considered indispensable.

Other objects will hereinafter appear.

The higher aliphatic alcohols containing from four to five carbon atoms, such as butyl alcohol, fusel oil, etc., have been used as ingredients of nitrocellulose film compositions, but so far as we are aware, they have always been associated with other and relatively expensive substances of low-volatility, often called softeners, such as camphor, triphenol phosphate, and amyl acetate, which have been considered necessary to impart essential properties to the composition or film. We have discovered that such other substances may be omitted without impair- Specification of Letters Patent.

films containin Patented May 31, 1921.

Application filed May 10, 1920. Serial No. 380,411.

ing the qualities of the composition or film'. In other words, we have found that compositions consisting simply of nitrocellulose, higher aliphatic alcohols and a volatile-common solvent function entirely satisfactorily in the film-making process; and the final films, consisting-essentially of nitrocellulose and such alcohols alone, possess all the hereinabove enumerated properties. In fact the simplified films have shown, when produced on a manufacturing scale, better wearing qualities and greater flexibility than camphor.

One illustratlon of our invention may be carried out as follows: With 100 parts of cellulose nitrate we thoroughly incorporate 30 to 100 parts of either fusel oil or butyl alcohol or a mixture thereof together with 300 to 1000 parts of methyl alcohol or 200 to 800 parts of acetone. The methyl alcohol and acetone are of the grades customarily used in this art and a mixture of them may be employed to the amount of 250 to 1000 parts, if desired. It will be noted that their boiling pointsare substantially below 100 C. Of course, equivalent volatile common solvents of nitrocellulose and said higher alcohols may be used. The butyl alcohol may be any of the isomers comprised under that term or a mixture of them. At present the synthetic .butyl alcohol is the most readily obtainable. The fusel oil may be of the grade ordinarily used in film manufacture. The nitrocellulose preferably is as evenly nitrated as possible. In the claims where the higher alcohols are referred to it will be understood that the commercial kinds known in this art are included.

The fusel oil and butyl alcohol are particularly adapted to the making of this simplified composition. They are excellent means for dehydrating nitrocellulose fibers, after nitration, and for lowering the fire risk when handling such fibers prior to dissolving them. They, therefore, can enter our composition directly with the nitrocellulose with which they have-been previously associated. But in the case of other high-boilers (which are not in general dehydrators or protectors and so are not previously associated with the nitrocellulose) a simple mixture of them alone with nitrocellulose could not be manufactured within the ordinary film-making apparatus intosheets of the desired thickness substantially all of the volatile solvent (methyl alcohol, acetone, etc.,) passing off and leavlng a film [of nitrocellulose with the higher alcohol alone. Any volatile solvent left in the film is inconsequential in amount and effect. In fact, by volatile solvent we mean to designate both in this description and in the following claims a solvent which volatilizes substantially entirely from the film. Such film has the required qualities hereinabove set forth.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

1. A composition consisting only of nitroday of April, 1920.

cellulose, aliphatic alcohols containing from 4 to 5 carbon atoms, and a volatile common solvent, the boiling point of which is substantially below 100 C.

2. A flowable sheet-forming composition consisting only of nitrocellulose, fusel oil, and a volatile common solvent.

3. A sheet-forming composition consisting only of 100 parts of nitrocellulose, to 100 parts of fusel oil, and 250 to 1000 parts of a methyl alcohol and acetone mixture.

4.. As an article of manufacture, a flowed sheet consisting only of nitrocellulose and aliphatic alcohols containing from 4 to 5 carbon atoms.

5. As an article of manufacture, a flowed sheet consisting only of nitrocellulose and 40 fusel oil.

Signed at Rochester, New York, this 24th PAUL C. SEEL. HENRY COMBS. RICHARD KEMP. 

